GIS Mapping Data Sources

GIS is a critical tool for planners; however, access to detailed, up-to-date data layers can be difficult to find. GIS can be used to understand community landscapes in many different planning functions and in a variety of
applications. In order to create informative maps and conduct useful analysis, planners need access to a range of data sets that provide information on a variety of topics and issue areas. Several national and state agencies have risen to meet this challenge and now maintain GIS data centers that include downloadable mapping files and associated data.

Caltrans
Earth uses a clean, straightforward, and user-friendly interface to provide
data on California’s transportation systems and other information. The site allows users to preview the layers
in a web mapping service, with the option to download the layer as either a
shapefile, which can be opened in GIS-based mapping software, or a KML file for
use in Google Earth. Most of the layers
in Caltrans Earth are linked to Caltrans’ database files and are simultaneously
updated as new information is added to the internal files.

The Caltrans
GIS Data Library includes data on the physical environment, transportation,
other infrastructure, political and administrative districts, cultural
geography, and earth imagery. The
mapping layers are organized into a table that shows a link to the metadata,
the form required to request access to the data, a sample image of the data,
the extent of the data (State, District or County), when the data was last
updated, whether it has been reviewed, the data topology (point or line), and data
sharing restrictions.

The
Cal-Atlas Geospatial Clearinghouse manages sharing of geospatial data between
California government agencies, partners, and stakeholders. The site allows users to search for data
layers, download data layers, upload data layers to share, and view maps and
web applications using geospatial data.
The mapping layers include information on the description, source, and
release date of data in the following categories: natural environments,
administrative and political boundaries, planning and development, elevation,
health, society, transportation, and earth imagery.

The National
Atlas Map Maker is a feature that allows users to assemble, view, and print
maps based on data layers comprised of information from the National Atlas of
the United States. The map layers are
organized by category in a table that allows users to view the data layer in
the Map Maker or to obtain background information and download raw data from
the map layer. The map layer categories
are agriculture, biology, boundaries, climate, environment, geology, history,
map reference, people, transportation, and water.

ARB’s GIS
Library includes GIS shapefiles and metadata for county, district, and air
basin boundaries; Federal air quality designations; State air quality designations;
and California air monitoring stations.
The site also includes a link to all commonly requested maps, many of
which include air quality management information by community and the option to
download the data used to create the maps.

The National
Map Viewer allows users to preview and download data layers compiled by the US
Geological survey. The data layers are
organized by base data layers (such as boundaries, topographic maps, land
cover, imagery, and structures), other featured data (such as ecosystems,
conserved lands, wetlands, and hazards), or user added content. The Map navigation tool offers some of the
data analysis and measurement functions found in GIS and Google Earth.

The
Geospatial Data Gateway is a catalogue of environmental and natural resources
data from the Natural Resources Conservation Service, Farm Service Agency, and
Rural Development. The site has a
user-friendly interface that separates the data download process into steps by
identifying what location you want data for (“Where”), the subject matter you are interested in
(“What”), and the type of file, projection, extent, and method of delivery you
want for your data (“How”).

The California
Department of Fish and Game data and maps webpage includes a list of links for all
departmental biological and geographic data.
The resources available include a GIS conservation data warehouse, an
online biogeographic mapping tool, a data portal for fishing and habitat
information, a document library, the California Natural Diversity Database for
endangered species, the Vegetation Classification and Mapping Program for
vegetation habitat, and the California Wildlife Habitat Relationships for
animal habitat.

The ESRI website
includes free data available for download, including: base maps, demographic
maps, reference maps and specialty maps.
Planners may be especially interested in the Census 2000 and Census 2010
TIGER/Line® shapefiles which include administrative and political boundaries,
demographic information, landmarks, transportation routes, water features, and
physical features.

The California
Department of Water Resources has compiled a list of major floodplain mapping
products developed by their office and the Federal Emergency Management
Agency. The maps include data for flood
insurance, floodplains, and flood protection zones.

A joint initiative of San Joaquin Valley Councils of Governments representing each of the region's eight counties, the San Joaquin Valley Air Pollution Control District, the Great Valley Center, and the Fresno State Community and Regional Planning Center